CLAS physics database search results Measurement E151M689 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_UL Stat. error Syst. error degrees 0.45 282 0.6887 0.6155 0.0517 0.65 114 -0.5822 0.5605 0.0466 0.65 126 -0.649 0.6468 0.0498 0.65 198 0.8361 0.8122 0.0593 0.65 222 0.9132 0.7175 0.0634 0.65 282 1.465 0.7284 0.0945 0.65 294 -0.9858 0.5095 0.0673 0.75 66 -0.4212 0.6285 0.0395 0.75 198 0.3192 0.7332 0.0358 0.75 222 0.58 0.6889 0.0465 0.75 234 1.0322 0.667 0.0699 0.75 282 0.5379 0.5235 0.0445 0.75 294 -0.2441 0.5994 0.0335 0.85 114 -0.7972 0.5631 0.0572 0.85 210 0.9273 0.6915 0.0642 0.85 222 -0.1223 0.6282 0.0309 0.85 234 1.1515 0.804 0.0766 0.85 246 -0.8192 0.5586 0.0584